Out of sight, out of cart? The effect of a Nudge(+) that reduced visibility of meat promotions on supermarket shopping behavior

Supermarkets have a major influence on food purchases and thus represent a good starting point for shifting consumption toward plant-based options. In a field study within a Dutch discount supermarket chain (10 intervention, 10 control stores, 11 weeks), we evaluated the effect of two interventions that were each implemented during half of the weeks on animal- and plant-based purchasing. The Nudge (N) intervention reduced fresh meat visibility by moving promotional products from end-cap displays to regular shelf locations with standard-sized price tags, and modestly increased plant-based visibility through recipes and footstep cues. In the Nudge+ (N+) intervention condition, communication materials containing a reflective cue aimed at activating plant-based goals were additionally placed at store entrances and the fresh meat aisle. Results showed that within the fresh meat and meat replacement section, the ratio of plant- to animal-based protein sold by weight, as well as plant-based sales, did not change significantly under either intervention. However, animal-based protein sales by weight significantly decreased within this section (N:-4.75%, N+:-6.37%), with no significant difference between interventions. Outside this section, neither intervention had conclusive effects on (non-targeted) animal-based purchases, though trends suggested animal-based purchasing increased. No changes in total store revenue were detected. Most shoppers did not notice the interventions yet were positive or neutral when informed. A nudge that includes reducing meat's promotional visibility appears to be an effective strategy for decreasing animal-based purchasing in a real-world supermarket while preserving commercial performance and customer acceptance.